How was John able to determine that we were not at the center of our Milky Way galaxy?

The correct answer is: By showing the distribution of globular clusters was not centered around us.

• We can see the particles in the sky even with the naked eye. This gives a sense that we are not in the center of the Milkyway galaxy.
• The scientists could survey the spherical distribution of globular clusters.
• By showing the distribution of globular clusters was not centered around us the scientists secluded that we are not in the center of the milky way galaxy.